Cesium Fluoride on Calcium Oxide as a Strongly Basic Catalyst. Synthesis of Flavones and Tobacco Alkaloids

Niobium containing aluminophosphate materials with AEL structure were prepared by the hydrothermal method. The chemical composition of the hydrogel was: 1 DIPA: 1 Al₂O₃: (1-x) P₂O₅: x Nb₂O₅: 80 H₂O, with x=0.025, 0.050, 0.075 and 0.100. The crystallization was carried out at temperature of 170°C for 72 h. The materials obtained were characterized by XRF, DRX, FTIR, TG and measurements of acidity. The characterization of the catalytic active sites were carried out in the isopropanol dehydration at temperature of 400°C, and WHSV of 1.6, 3.2, 4.8, 6.4 and 8.0 h^-1 . The samples showed good catalytic activity with selectivity to propene. This revised version was published online in June 2006 with corrections to the Cover Date.